My public variables are lost when I convert my game object into a prefab

I have a boost power up that works perfectly fine in the hierarchy. However, when I covert it into a prefab, the variable disconnect?

Incase the code is confusing. I shall explain

powerUpBoostScript - This increases the speed of my player when it hits the power up pickupEffect - This is the animation that instantiates when you pick up the power up Boost - This is the sprite which has the graphic of a boost appear when you pick up the power up

(Code Below)

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class PowerUpBoost : MonoBehaviour {
 
     public GameObject powerUpBoostScript;
     public GameObject pickupEffect;
     public GameObject Boost;
 
 
     public float duration;
     private bool boostOn = false;
 
 
     void OnTriggerEnter2D (Collider2D other)
     {
         if (other.CompareTag ("Player")) 
         {
             StartCoroutine(Pickup (other));
         }
     }
         
 
     IEnumerator Pickup(Collider2D player)
     {
         //PowerUp explosion (Animation)
         Instantiate (pickupEffect, transform.position, transform.rotation);
 
         //Boost jets appear
         if (boostOn == false) 
         {
             Boost.SetActive (true);
             boostOn = true;
         }
 
         //Boost speed increases
         PlayerController boostSpeedScript = powerUpBoostScript.GetComponent<PlayerController> ();
         boostSpeedScript.speed = 5f;
 
         //Disables the collider2D around PowerUp
         GetComponent<Collider2D> ().enabled = false;
         GetComponent<SpriteRenderer> ().enabled = false;
 
         yield return new WaitForSeconds (duration);
 
         //Boost speed decreases
         boostSpeedScript.speed = 3f;
 
         //Boost jets disappear
         if (boostOn == true) 
         {
             Boost.SetActive (false);
             boostOn = false;
         }
 
         Destroy (gameObject);
     }
         
 
 
 }